Register or Login To Download This Patent As A PDF
|United States Patent Application
;   et al.
April 12, 2012
5-CNAC AS ORAL DELIVERY AGENT FOR PARATHYROID HORMONE FRAGMENTS
Pharmaceutical compositions for the effective oral delivery of a
parathyroid hormone, PTH, as well as methods for administration of the
compositions are provided. Additionally, methods for stimulating new bone
formation and treating and/or preventing osteoporosis are also provided.
Azria; Moise; (Basel, CH)
; Bateman; Simon David; (Randolph, NJ)
December 15, 2011|
|Current U.S. Class:
|Class at Publication:
||A61K 38/29 20060101 A61K038/29; A61P 19/10 20060101 A61P019/10; A61P 19/00 20060101 A61P019/00|
22. A pharmaceutical composition for oral delivery comprising recombinant
PTH (1-34) and N-(5-chlorosalicyloyl)-8-aminocaprylic acid (5-CNAC)
23. A method for orally administering an effective dose of PTH comprising
orally administering to a patient in need of PTH a pharmaceutical
composition comprising recombinant PTH (1-34) and 5-CNAC disodium salt.
24. A method of stimulating new bone formation comprising orally
administering to a patient in need of new bone formation a pharmaceutical
composition comprising a therapeutically effective amount of recombinant
PTH (1-34) and 5-CNAC disodium salt.
25. A method of treating osteoporosis comprising orally administering to
a patient in need of said treatment a pharmaceutical composition
comprising a therapeutically effective amount of recombinant PTH (1-34)
and 5-CNAC disodium salt.
BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to the oral delivery of parathyroid
hormone (PTH). The mammalian parathyroid hormones, e.g. human (hPTH),
bovine (bPTH) and porcine (pPTH), are single polypeptide chains of 84
amino acid residues having molecular weights of approximately 9500.
Specifically, the present invention relates to PTH fragments
incorporating at least the first 28 N-terminal amino acid residues (PTH
(1-28)) up to and including the first 41 N-terminal amino acid residues
(PTH (1-41)). More particularly, the invention is directed to
pharmaceutical compositions for the oral delivery of PTH, said
compositions comprising PTH (1-28) to (1-41) and
N-(5-chlorosalicyloyl)-8-aminocaprylic acid (5-CNAC).
 2. Description of the Related Art
 PTH studies done in animals and humans with PTH, PTH-related
peptides, and PTH analogues have demonstrated its usefulness in
increasing bone formation and bone resorption and have prompted interest
in its use for the treatment of osteoporosis and related bone disorders.
However, the oral delivery of PTH in mammals has proven difficult due, at
least in part, to the insufficient stability of PTH in the
gastrointestinal tract as well as the inability of PTH to be readily
transported through the intestinal walls into the blood stream.
 U.S. Pat. No. 5,773,647 (the `647 patent) describes 193 carrier
compounds useful for the delivery of active agents, including PTH. One of
the carrier compounds expressly described therein is
N-(5-chlorosalicyloyl)-8-aminocaprylic acid (5-CNAC) having the formula
 Example 2 in Column 6 of the `647 patent describes the preparation
of 11 different dosing compositions some intracolonic (IC) and some oral
gavage (PO) each containing parathyroid hormone and a carrier, the
carrier being different for each composition. An IC dosing composition
was prepared using 5-CNAC as the carrier. Example 3 therein describes in
vivo tests carried out dosing male Sprague-Dawley rats with the dosing
solutions prepared in Example 2. Blood samples were collected and the
serum PTH concentration was quantified for each rat.
 Surprisingly, it has now been found that 5-CNAC in combination with
specific PTH fragments, i.e. PTH fragments incorporating at least the
first 28 N-terminal amino acid residues (PTH (1-28)) up to and including
the first 41 N-terminal amino acid residues (PTH (1-41)) when orally
administered gives unexpectedly high PTH serum levels relative to other
PTHs and other carriers and provide a sharp C.sub.max allowing for a bone
SUMMARY OF THE INVENTION
 Accordingly, the present invention is directed to pharmaceutical
compositions suitable for oral delivery of PTH fragments and to methods
of administering such compositions.
 Specifically, the instant invention is directed to a pharmaceutical
composition for oral delivery comprising a therapeutically effective
amount of a PTH fragment and 5-CNAC, said PTH fragment selected from PTH
(1-28) to PTH (1-41). Preferably, the PTH is human parathyroid hormone,
 In another embodiment, the invention is directed to a method for
orally administering an effective dose of PTH comprising orally
administering to a patient in need of PTH a pharmaceutical composition
comprising a therapeutically effective amount of a PTH fragment and
5-CNAC, said PTH fragment selected from PTH (1-28) to PTH (1-41).
 The invention is also directed to a method of stimulating new bone
formation comprising orally administering to a patient in need of new
bone formation a pharmaceutical composition comprising a therapeutically
effective amount of a PTH fragment and 5-CNAC, said PTH fragment selected
from PTH (1-28) to PTH (1-41).
 In a further embodiment, the invention is directed to a method of
treatment or prevention of osteoporosis comprising orally administering
to a patient in need of said treatment or prevention a pharmaceutical
composition comprising a therapeutically effective amount of a PTH
fragment and 5-CNAC, said PTH fragment selected from PTH (1-28) to PTH
 In a still further embodiment, the invention is directed to the use
of 5-CNAC for the preparation of a pharmaceutical composition suitable
for the oral delivery of PTH fragments selected from PTH (1-28) to PTH
 Further features and advantages of the invention will become
apparent from the following following detailed description of the
DETAILED DESCRIPTION OF THE INVENTION
 The PTH fragments can be of any parathyroid hormone, particularly
mammalian parathyroid hormone, e.g. human (hPTH), bovine (bPTH), and
porcine (pPTH) and particularly hPTH and will incorporate at least the
first 28 N-terminal residues (PTH (1-28)) up to and including the first
41 N-terminal residues (PTH (1-41)) and include without limitation PTH
(1-28), PTH (1-31), PTH (1-34), PTH (1-37), PTH (1-38) and PTH (1-41).
Human parathyroid hormone (1-34) is particularly preferred. These
parathyroid hormone fragments are commercially available or can be
obtained recombinantly or by peptide synthesis.
 For purposes of the instant invention, the 5-CNAC, i.e.
N-(5-chlorosalicyloyl)-8-aminocaprylic acid, can be the free acid,
analogs thereof, its monosodium and disodium salts, ethanol solvates of
the sodium salts and the monohydrates of the sodium salts and any
combinations thereof. The free acid, the disodium salt of 5-CNAC and the
monohydrate thereof are particularly useful.
N-(5-chlorosalicyloyl)-8-aminocaprylic acid is described in the
aforementioned `647 patent, the contents of which are hereby incorporated
by reference, and can be made by methods described therein. The sodium
salts and alcohol solvates and hydrates thereof are described in WO
00/059863, along with methods for preparing them.
 The disodium salt may be prepared from the ethanol solvate by
evaporating or drying the ethanol solvate by methods known in the art to
form the anhydrous disodium salt. Drying is generally carried out at a
temperature of from about 80 to about 120.degree. C., preferably from
about 85 to about 90.degree. C., and most preferably at about 85.degree.
C. The drying step is generally performed at a pressure of 26'' Hg or
greater. The anhydrous disodium salt generally contains less than about
5% by weight of ethanol and preferably less than about 2% by weight of
ethanol, based on 100% total weight of anhydrous disodium salt.
 The disodium salt of N-(5-chlorosalicyloyl)-8-aminocaprylic acid
can also be prepared by making a slurry of
N-(5-chlorosalicyloyl)-8-aminocaprylic acid in water and adding two molar
equivalents of aqueous sodium hydroxide, sodium alkoxide or the like.
Suitable sodium alkoxides include, but are not limited to, sodium
methoxide, sodium ethoxide, and combinations thereof.
 A still further method of preparing the disodium salt is by
reacting N-(5-chlorosalicyloyl)-8-aminocaprylic acid with one molar
equivalent of sodium hydroxide to form a monosodium salt and then adding
an additional one molar equivalent of sodium hydroxide to yield the
 The disodium salt can be isolated as a solid by concentrating the
solution containing the disodium salt to a thick paste by vacuum
distillation. This paste may be dried in a vacuum oven to obtain the
disodium salt of N-(5-chlorosalicyloyl)-8-aminocaprylic acid as a solid.
The solid can also be isolated by spray drying an aqueous solution of the
 The ethanol solvates, as described in the aforementioned WO
00/059863, include, but are not limited to, a molecular or ionic complex
of molecules or ions of ethanol solvent with molecules or ions of the
disodium salt of N-(5-chlorosalicyloyl)-8-aminocaprylic acid. Typically,
the ethanol solvate contains about one ethanol molecule or ion for every
molecule of disodium salt of N-(5-chlorosalicyloyl)-8-aminocaprylic acid.
 The ethanol solvate of the disodium salt of
N-(5-chlorosalicyloyl)-8-aminocaprylic acid can be prepared by dissolving
N-(5-chlorosalicyloyl)-8-aminocaprylic acid in ethanol. Typically, each
gram of N-(5-chlorosalicyloyl)-8-aminocaprylic acid is dissolved in from
about 1 to about 50 mL of ethanol and generally, from about 2 to about 10
mL of ethanol. The N-(5-chlorosalicyloyl)-8-aminocaprylic acid/ethanol
solution is then reacted with a molar excess of a sodium containing salt,
such as a monosodium containing salt, relative to
N-(5-chlorosalicyloyl)-8-aminocaprylic acid, i.e. for every mole of
N-(5-chlorosalicyloyl)-8-aminocaprylic acid there is more than one mole
of sodium cations, yielding the ethanol solvate. Suitable monosodium
salts include, but are not limited to, sodium hydroxide; sodium
alkoxides, such as sodium methoxide and sodium ethoxide; and any
combination of the foregoing. Preferably, at least about two molar
equivalents of the monosodium containing salt are added to the ethanol
solution, i.e. for every mole of N-(5-chlorosalicyloyl)-8-aminocaprylic
acid there is at least about two moles of sodium cations. Generally, the
reaction is performed at or below the reflux temperature of the mixture,
such as at ambient temperature. The ethanol solvate is then recovered by
methods known is the art, such as, concentration of the resulting slurry
at atmospheric distillation, cooling the concentrated slurry and
filtering the solid. The recovered solid can then be vacuum dried to
obtain the ethanol solvate.
 The hydrates of the disodium salts of the
N-(5-chlorosalicyloyl)-8-aminocaprylic acid may be prepared by drying the
ethanol solvate to form an anhydrous disodium salt, as described above,
and hydrating the anhydrous disodium salt. Preferably, the monohydrate of
the disodium salt is formed. Since the anhydrous disodium salt is very
hydroscopic, the hydrate forms upon exposure to atmospheric moisture.
Generally, the hydrating step is performed at from about ambient
temperature to about 50.degree. C., preferably ambient temperature to
about 30.degree. C. and in an environment having at least 50% relative
humidity. Alternatively, the anhydrous disodium salt may be hydrated with
 The amount of PTH fragment to be administered is generally an
amount effective to stimulate new bone formation i.e. a therapeutically
effective amount. This amount will necessarily vary with the age, size,
sex and condition of the subject to be treated, the nature and severity
of the disorder to be treated and the like. However, the amount can be
less than that amount when a plurality of the compositions are to be
administered, i.e., the total effective amount can be administered in
cumulative dosage units. The amount of PTH can also be more than the
effective amount when the composition provides sustained release of the
pharmacologically active agent. The total amount of PTH to be used can be
determined by methods known to those skilled in the art. However, in
general, satisfactory results will be obtained systemically at daily
dosages of from about 0.001 .mu.g/kg to about 10 mg/kg animal body
weight, preferably 1 .mu.g/kg to about 6 .mu.g/kg body weight.
 The pharmaceutical compositions of the present invention typically
contain a delivery effective amount of 5-CNAC, i.e. an amount sufficient
to deliver the PTH for the desired effect. Generally, the 5-CNAC is
present in an amount of 2.5% to 99.4% by weight, more preferably 25% to
50% by weight of the total composition.
 Oral administration of the pharmaceutical compositions according to
the invention can be accomplished regularly, e.g. once or more on a daily
or weekly basis; intermittently, e.g. irregularly during a day or week;
or cyclically, e.g. regularly for a period of days or weeks followed by a
period without administration.
 The dosage form of the pharmaceutical compositions of the instant
invention can be any known form, e.g. liquid or solid dosage forms.
 The liquid dosage forms include solution emulsions, suspensions,
syrups and elixirs. In addition to the PTH and 5-CNAC, the liquid
formulations may also include inert excipients commonly used in the art
such as, solubilizing agents e.g. ethanol; oils such as cottonseed,
castor and sesame oils; wetting agents; emulsifying agents; suspending
agents; sweeteners; flavorings; and solvents such as water.
 The solid dosage forms include capsules, soft-gel capsules,
tablets, caplets, powders, granules or other solid oral dosage forms, all
of which can be prepared by methods well known in the art.
 The pharmaceutical compositions may additionally comprise additives
in amounts customarily employed including, but not limited to, a pH
adjuster, a preservative, a flavorant, a taste-masking agent, a
fragrance, a humectant, a tonicifier, a colorant, a surfactant, a
plasticizer, a lubricant such as magnesium stearate, a flow aid, a
compression aid, a solubilizer, an excipient, a diluent such as
microcrystalline cellulose, e.g. Avicel PH 102 supplied by FMC
corporation, or any combination thereof. Other additives may include
phosphate buffer salts, citric acid, glycols, and other dispersing
 The composition may also include one or more enzyme inhibitors,
such as actinonin or epiactinonin and derivatives thereof; aprotinin,
Trasylol and Bowman-Birk inhibitor.
 Further, a transport inhibitor, i.e. a p-glycoprotein such as
Ketoprofin, may be present in the compositions of the present invention.
 The solid pharmaceutical compositions of the instant invention can
be prepared by conventional methods e.g. by blending a mixture of the PTH
fragment, the 5-CNAC, and any other ingredients, kneading, and filling
into capsules or, instead of filling into capsules, molding followed by
further tableting or compression-molding to give tablets. In addition, a
solid dispersion may be formed by known methods followed by further
processing to form a tablet or capsule.
 Preferably, the ingredients in the pharmaceutical compositions of
the instant invention are homogeneously or uniformly mixed throughout the
solid dosage form.
 Parathyroid hormones are indicated for preventing or treating all
bone conditions which are associated with increased calcium depletion or
resorption or in which stimulation of bone formation and calcium fixation
in the bone is desirable, e.g. osteoporosis of various genesis (e.g.
juvenile, menopausal, post-menopausal, post-traumatic, caused by old age
or by corticoid-steroid therapy or inactivity), fractures, osteopathy,
including acute and chronic states associated with skeletal
demineralization, osteo-malacia, periodontal bone loss or bone loss due
to arthritis or osteoarthritis or cancer (e.g. bone metastis) or for
 Parathyroid hormones are particularly indicated for preventing or
treating osteoporosis of various genesis.
 According to a further embodiment of the invention, the PTH may be
employed as adjunct or adjuvant to other therapy, e.g. a therapy using a
bone resorption inhibitor, for example as in osteoporosis therapy, in
particular a therapy employing calcium, a calcitonin or an analogue or
derivative thereof, e.g. salmon, eel or human calcitonin, a steroid
hormone, e.g. an estrogen, a partial estrogen agonist or
estrogen-gestagen combination, a SERM (Selective Estrogen Receptor
Modulator) e.g. raloxifene, lasofoxifene, TSE-424, FC1271, Tibolone
(Livial.RTM.), vitamin D or an analogue thereof or an activator of PTH
release, or bisphosphonates, e.g. clodronic acid, etidronic acid,
pamidronic acid, aledronic acid, ibandronic acid, zoledronic acid,
risedronic acid or tiludronic acid and salts and hydrates thereof.
 When the PTH is administered in conjunction with, e.g. as an
adjuvant to bone resorption inhibition therapy, dosages for the
co-administered inhibitor will of course vary depending on the type of
inhibitor drug employed, e.g. whether it is a steroid or a calcitonin, on
the condition to be treated, whether it is a curative or preventive
therapy, on the regimen and so forth.
 The oral administration of the present invention may be to any
animal in need thereof, including, but not limited to, mammals, such as
rodents, cows, pigs, dogs, cats, and primates, particularly humans.
 The following examples serve to further illustrate the invention.
 The following capsules are prepared as follows: Capsules prepared
from 800 .mu.g hPTH* (Capsule 1A) Capsules prepared from 400 mg
5-CNAC**/800 .mu.g hPTH* (Capsule 1B) *The PTH fragment is human
parathyroid hormone, fragment 1-34 commercially available from Sigma.
**The 5-CNAC is the disodium salt of
 The hPTH only capsules are prepared by weighing out 400 .mu.g of
the hPTH and placing it directly into each capsule. The hPTH/5-CNAC
capsules are prepared as dry blends by weighing out the individual
components blending them together to make a homogeneous mix and then hand
filling 400 mg of the mix into each capsule;
 The capsules prepared in Example 1 are administered to Rhesus
monkeys as follows: four monkeys in a group are each dosed with one
capsule prepared as in Example 1 as follows:
 The Rhesus monkeys fast overnight prior to dosing and are
restrained in chairs fully conscious, for the duration of the study
period. The capsules are orally administered via a gavage tube followed
by 10 ml of water.
 Blood samples are collected at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4,
5, and 6 hours after administration. Plasma hPTH levels are determined by
radioimmunoassay. The primate plasma PTH results from each group of
monkeys are averaged and the maximum mean plasma calculated. The results
for the PTH only group are reported in Table 1 and the results for the
hPTH/5-CNAC group are reported in Table 2.
hPTH PLASMA CONCENTRATIONS (pg/mL) AFTER
ORAL ADMINISTRATION TO THE RHESUS MONKEY
Dose: 1 Capsule 1D
imal Time [hours]
no. 0 0.25 0.50 0.75 1 1.5 2 3 4 5 6
R927 0 0 0 0 0 0 0 0 0 0 0
S982 0 0 0 0 0 0 0 0 0 0 0
Mean 0 0 0 0 0 0 0 0 0 0 0
SD 0 0 0 0 0 0 0 0 0 0 0
SEM 0 0 0 0 0 0 0 0 0 0 0
LLOQ = 25 pg/mL, concentrations below LLOQ were set to zero.
hPTH PLASMA CONCENTRATIONS (pg/mL) AFTER
ORAL ADMINISTRATION TO THE RHESUS MONKEY
Dose: 1 Capsule 1B
imal Time [hours]
no. 0 0.25 0.50 0.75 1 1.5 2 3 4 5 6
R944 0 83 191 300 360 262 154 35 0 0 0
S963 0 127 332 663 1258 150 34 0 0 0 0
Mean 0 105 262 482 809 206 94 17 0 0 0
SD 0 31 100 257 635 79 85 25 0 0 0
SEM 0 22 71 182 449 56 60 17 0 0 0
 As can be seen from the data in Tables 1 and 2, the 5-CNAC
significantly facilitates the oral delivery of the hPTH fragment. In
addition, the data in Table 2 indicate a sharp C.sub.max in the PTH
plasma profile allowing for a bone formation effect.
 The foregoing embodiments and examples are given merely to
illustrate the instant invention and are not intended to be limiting.
Numerous other embodiments and variations are within the scope of the
invention and readily accessible to those skilled in the art.
* * * * *